On the go and no time to finish that story right now? Your News is the place for you to save content to read later from any device. Register with us and content you save will appear here so you can access them to read later.

Operators say fire damage to the newly-opened $20m mountain bike park above Christchurch is "a lot worse than we originally thought", with around two thirds of the park charred by last month's massive Port Hills blaze.

The Rural Fire Authority handed back Christchurch Adventure Park (CAP) on Friday, marking the start of what park bosses said will be a "fairly long make-safe and damage assessment process".

They said it would be months, not weeks, before the true extent of the damage was known and insurance was determined, before any repairs could begin.

Much of the forest plantation, owned by timber company McVicar Holdings and leased to CAP, has been burned. Thousands of blackened trunks scar the once-picturesque hillside overlooking the city across the Canterbury Plains to the Southern Alps.

The raging inferno, which first roared through the park's valleys on the afternoon of Wednesday, February 15, was kept away from the village, including office buildings and cafe.

Access is limited as the park is considered dangerous. Picture / Matt Simons

Access is limited as the park is considered dangerous. Picture / Matt Simons

Fire crews worked through that night to keep the blaze at bay. It got within 50m of the main infrastructure.

However, the fires burned out of control in other areas of the park, including parts where the chairlift and two ziplines traverse.

Park officials are yet to fully gauge the damage to the Austrian custom-made chairlift, although they know at least some chairs have been burned. They fear its 36-tonne main cable could require replacement from Europe.

"It's actually a lot worse than we originally thought," park spokeswoman Anne Newman said of the "devastating" damage.